our Staff

Get to know more about our staff (in alphabetical order)!

Captain Evan Clark

Waterkeeper

Captain Evan has spent more than 20 years focused on learning from, living with, working upon and playing around rivers. He's traveled the length of the Mississippi river and many of its tributaries, the Allegheny, Ohio, Monongahela, Missouri, Tennessee, Cumberland, Atchafalaya and other waters on boats he built himself. He settled in Pittsburgh in 2005 and has worked with various river based nonprofits, including Allegheny Cleanways on the Tireless project where he's led thousands of volunteers cleaning more than 180 miles of riverbanks in Allegheny County. Together they've collected more than a million pounds of mostly plastic based garbage, tires, and human made debris. You can also find Captain Evan along our rivers as a part time captain on the hybrid electric vessel Explorer, Rivers of Steel's riparian biology educational and tour boat. He also lives on and swims in the Allegheny from his houseboat. In his limited spare time, Evan enjoys building and fixing boats with friends and traveling on distant waters. 

Jess Friss

​​Director of Community Programs

Jess Friss grew up in Pittsburgh and joined Three Rivers Waterkeeper after serving two terms in AmeriCorps in the Public Allies Pittsburgh program where she learned and practiced equity focused leadership skills for social impact, capacity-building non-profit work, and asset-based community development. During her program terms she was placed at the Pennsylvania Center for Women and Politics at Chatham University as their Outreach Coordinator. Jess graduated with honors from Robert Morris University in 2019 with a B.S. in Environmental Science. Her honors thesis explored "The Relationship of Racial and Socioeconomic Composition and Environmental Quality in Two Pittsburgh Neighborhoods". Jess is committed to lifelong learning and earned an EcoDistricts Accredited Professional certificate in 2020.

​​​Markeea hart​

​Communications Manager

Meet Markeea Hart, a powerhouse of creativity and enthusiasm! With a flair for transforming ideas into vibrant realities, Markeea is your go-to expert for all  things social media, project management, and marketing magic. As a Certified Scrum Master, Markeea knows how to juggle multiple projects with ease, all while
maintaining a cool and collected demeanor. Her knack for turning complex  challenges into smooth, successful outcomes is truly something to behold. Whether she's orchestrating a high- energy marketing campaign or diving into the nitty-gritty of CRM systems, Markeea brings a burst of innovation and fun to every task. Markeea is the visionary behind Girls Running Sh**(GRS), a platform she created to inspire and uplift women everywhere. From organizing fabulous events to crafting eye-catching social media content, she’s all about spreading positivity and empowering others. With GRS, she’s not just running things—she’s running them with style!

Hannah Hohman

​Projects Coordinator

Hannah Hohman is a lifelong resident of Western Pennsylvania with a longstanding passion for the environment, especially the region’s rivers and streams.  She graduated from Penn State College of Agricultural Sciences with a degree in Community, Environment, and Development with a concentration in economic development. During her time at Penn State, she worked with Penn State’s Sustainability Institute and Penn State Athletics to relaunch a large-scale recycling program at Penn State football game tailgates. Hannah’s interest in trash and how it impacts community and the environment lead her to a position with Allegheny CleanWays coordinating for their riverfront cleanup program, the Tireless Project. With her extensive knowledge of the region's rivers, she is excited to tackle pollution from a different angle. Hannah lives right along the Youghiogheny River in Elizabeth Township and spends most of her free time enjoying the outdoors. 

​​​Heather Hulton Vantassel, Phd​​

Executive Director 

Heather Hulton VanTassel is an environmental conservationist passionate about nature-based solutions that lead to the sustainability of our planet and equality for all. Heather’s passion began in a small rural community in Western Pennsylvania and flourished as a first-generation college student at Carlow University majoring in Biology. Heather went on to earn her doctorate degree in Evolution, Ecology, and Organismal Biology at The University in California, Riverside (UCR). Heather has held positions at UCR’s Center for Conservation Biology as a Research Specialist, Audubon South Carolina as a Program Manager of Sustainable Solutions, The Nature Conservancy in South Carolina as the State Conservation Coordinator, and at The Carnegie Museum of Natural History as the Assistant Director of Science and Research. Heather has had formal training and certification as a Master Naturalist in South Carolina’s Lowcountry, Project Management Professional, Wetland Delineator, and Diversity, Equity, and Inclusion in the Workplace practitioner.  Heather has a strong passion for both the environment and equity and believes that working towards sustainability also requires an equal effort towards social environmental justice. In her free time, Heather enjoys hiking, spending time with her friends, family and pets, and (of course) recreating on our Three Rivers! 

Koa Reitz

Environmental Scientist

Koa Reitz earned her degree from the University of Pittsburgh in Ecology and Evolution. Her interests include environmental conservation and restoring the ecological health of our waterways and public lands. Her sustainability capstone project at the University of Pittsburgh involved creating a citizen science project to help track plastic pollution from a local cracker plant. As a lifelong Pittsburgher, she became passionate about the health of our many waterways and aware of the connection between them and the city and people around them. In her free time she enjoys going on hikes, exploring the city, and crocheting.

Tamiya Thomas

Environmental Steward, PMSC AmeriCorps Member

​Tamiya Thomas is a graduate of PennWest University California ( Formerly California University of Pennsylvania) with a Bachelor’s in Business Administration and Management and minors in Musical Theatre and Tourism Events. She recently finished a three and a half month restoration project in Alaska! Through the Student Conservation Association program, she had the opportunity to camp in small town Hope, Alaska and revegetate Phase Two of the Resurrection Creek. These project phases focus on rebuilding the natural flow and flood banks of the river that were destroyed from decades of mining. Tamiya also worked with the U.S. Forest Service, contracted construction crews, and the town of Hope in restoring a beautiful landmark! Tamiya has interests in Performing Arts (singing, dancing, acting), Video Essays on pop culture and film media, Reading and Writing, Conservation, Interior Decoration, and Fashion.

Sierra weir

Community Organizer

Sierra Weir is a natural pigment artist who grew up on the Allegheny River, earned her B.A. in Biochemistry & Molecular Biology, and found her way to 3RWK after finding a passion for science communication and advocacy. She is an amateur entomologist and mycologist who works from environmental justice and community-centric frameworks with the goals of learning, sharing, and fostering interconnectedness between people, ecosystems, waterways, and the land itself. Sierra comes from a family of coal miners, industry laborers, canners and chemists, and feels lots of love for the ancient and alive Southwestern Pennsylvania. When she’s not working on community programs or alchemizing local pigments, she traipses around on roller-skates, dumpster dives, and sprints to the library before her holds expire.

Board of Directors

September 2024

Tim Fitchett
President

Tim Fitchett is a staff attorney and resident director at Fair Shake Environmental Legal Services, a non-profit environmental law firm based out of Pittsburgh, PA and Akron, OH. Tim is also on the Board for Calliope House, an organization devoted to promoting folk music in Pittsburgh and the surrounding area. Tim joined Three Rivers Waterkeeper in December of 2020 and is excited to help our rivers flourish. ​

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Rachel cook
tReasurer

​Rachel joined the Global Waterkeeper Alliance team in 2007 as Operations Assistant and has held various titles over the years. Rachel has always had a passion for the outdoors and conservation and has experience with natural resource management, wildlife photography, ecotourism, and various facets of sustainability. Before starting at Waterkeeper Alliance, Rachel learned about the organization while volunteering with and working for Hackensack Riverkeeper at their canoe and kayak livery in Secaucus, NJ. She holds a B.A. in Environmental Studies from the University of Vermont, an M.S. in Sustainability Management from Columbia University, and is a LEED Green Associate. Rachel lives in the Hudson Valley, and while not in the office she can most likely be found skiing, backpacking, hiking, at a crossfit class, or cheering for the Pittsburgh Steelers.

Kate zidar
acting SECRETARY

Kate Zidar is a Biologist, Environmental Planner, and Geochemist who grew up in the South Hills of Pittsburgh. Her professional focus is on the intersection of waste management and green infrastructure. Kate earned an MS at the Pratt Institute, where she taught graduate courses for seven years.  She was a founding member of the Stormwater Infrastructure Matters (S.W.I.M.) Coalition, a policy think-and-do tank that figured centrally in establishing Green Infrastructure as a mainstream practice in New York City. She founded the North Brooklyn Compost Project, a collective of 400+ volunteers that “made the road by walking”, preceding city-wide collection of organic waste in NYC.  Kate travels extensively and lived aboard her sailboat for five years, between the US East Coast, the Caribbean, and Central America. Today, she applies this broad skill set in southwestern PA. Kate can be found puttering around in her dinghy on the Allegheny, turning the compost pile in the Garden of Etna, or conspiring in Millvale to Save Maxo Vanka.

EMILY CONSTANTINE MERCURIO,
​PHD, PG
BOARD MEMBER

Emily Constantine Mercurio is  a big thinker and a lifelong learner. She is an experienced geoscientist and an expert in mapping, field geology, GIS, remote sensing, and geospatial technology. As co-founder and CEO of CivicMapper, Emily draws upon more than 20 years of experience as a leader in map-based technology projects. Her current work is focused on creating spatially-enabled applications that empower decision making on the front lines of climate change, infrastructure, and social equity. Emily is a licensed professional geologist in the state of Pennsylvania. In addition to service on the Three Rivers Waterkeeper board, she also sits on the board of the Pennsylvania State University Graduates of Earth and Mineral Science. She enjoys gardening, visiting hot springs, making art, and spending time on the water with family and friends.

Sean Brady
BOARD MEMBER

Sean is the Executive Director of Hollow Oak Land Trust, a conservation organization that protects and connects greenspace in the Pittsburgh International Airport Corridor. With a BA in Biology from Allegheny College and an MA in Professional Writing from Carnegie Mellon University, Sean helped build Venture Outdoors as a regional leader in outdoor recreation from its inception in 2001 to 2010. He also served as Development Director for Riverlife, supporting sustainable riverfront development in downtown Pittsburgh. Currently, Sean manages the six conservation areas owned by Hollow Oak Land Trust and works with municipalities and private landowners to develop greenways in the airport corridor.

Josh Powell
bOARD mEMBER

Joshua Powell is an engineer at Broadcom, Inc., a designer, and supplier of semiconductors and infrastructure software products. Joshua has spent the past 15 years working closely with non-profit organizations focused on environmental conservation and restoration by building award-winning software. Joshua joined Three Rivers Waterkeeper in December 2020. In his free time, he enjoys gardening and spending time outdoors with his family.

Annie Guadagnino
BOARD MEMBER

Annie Guadagnino is the Program Coordinator for the The Pennsylvania Center for Women and Politics (PCWP) at Chatham University. Before joining PCWP's staff in 2012 she was a Campaign Director for Fund for the Public Interest and a Campus Organizer for the Public Interest Research Group. Annie served from 2017 to 2019 as a member of the YWCA Young Leaders Board. Annie is a 2009 graduate of the University of Michigan with a BA in Environmental Studies and a minor in Political Science.

Vishal vyas
bOARD mEMBER

Vishal Vyas brings with him an impressive wealth of experience, spanning over two decades, in various key domains such as Procurement, Supplier Relationship Management, Marketing, Product Management, and Program Management. His expertise has been honed through dynamic roles in both the Automotive and Medical Device Industries, making him a true global professional. Currently, Vishal holds the prestigious position of Sourcing Leader with Philips Healthcare, a role that showcases his exceptional leadership and strategic skills in the world of healthcare and technology.
 
Vishal holds a Bachelor of Science degree in Plastics Engineering from Ferris State University, demonstrating his strong foundation in engineering. In addition to that, he has further enriched his knowledge by completing an Executive MBA program at Cleveland State University, equipping him with valuable management and leadership skills. To top it off, Vishal has earned a Business Analytics certification from Harvard Business School, demonstrating his commitment to staying at the forefront of business innovation and data-driven decision-making.
 
Vishal Vyas is a dedicated family man. He resides in Gibsonia, Pennsylvania, with his wife, Minal Vyas, and their two wonderful children, Avish and Arya, who undoubtedly serve as a source of inspiration and motivation for his contributions to our organization. Vishal is not just a leader in the corporate world but also an active and engaged member of his community. He takes an active role in several community activities, reflecting his dedication to making a positive impact beyond the boardroom.

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